I had a hard time with this myself. I downloaded the app "zedge", and searched a lot through there. If you search under the keyword "business", "telephone", etc., you can find a few. I found one that I sort of liked, but wasn't perfect. So I grabbed it off the microSD card (which is where zedge stores the ringtones once you download them), and changed it to my liking using the freeware "audacity". I believe there is an app that can allow you to modify ring tones, but I had more freedom of customization in audacity.